Internal-combustion engine



Dec. 31, 1929. A. CRAIGON INTERNAL COMBUSTION ENGINE 192'? 2 Sheets$heet 1 Original Filed Nov. 2

- INVENTDR.

Dec. 31, 1929. A. CRAIGON INTERNAL COMBUSTION ENGINE Original Filed Nov 2, 1927 2 Sheets-Shea; 2

- INVENIDR Patented Dec. 31, 1929 rrno STAT ADAM CEAIGON, OF HAMILTON, ONTARIO, CANADA INTERNAL-COMBUSTION ENGINE Application. filed November 2, 1927, Serial No. 230,656. Renewed November 18, 1929.

his invention relates to engines of the Diesel type in which the fuel is injected into air compressed to raise its temperature suiliciently to cause the ignition of the fuel, and my object is to devise an engine of this type in which a substantial increase of power per unit of weight may be obtained as compared with existing engines, and more particularly to improve in detail the engine described and claimed in my prior United States Patent No.

1,635,742, dated'July 12th, 1927.

I attain my object by means of constructions which may be briefly described as tollows: A single unit of my engine comprises two cylinders, and co-o-perating parts, ar-

ranged side by side, and a plurality of these units may be employed for a single crank shaft as circumstances may dictate. Each cylinder is provided with a trunk piston and a stationary piston fitted in the sleeve of the trunk piston, whereby two combustion chambers are formed, one between the trunk piston and the end of the cylinder and one between the inside of the head of the trunk piston and the stationary piston; and ports and passages in the cylinder walls and ports in the trunk pistons whereby air or gases may be caused to flow seriatim through either pair of combustion chambers according to the po so sition of the trunk piston, the passages between the pistons being three in number so that when scavenging is taking place two channels are provided between thechambers of one pair or the other, as the case may be, adjacent the opposite ends thereof. Further features of the invention lie in the means pro vided for cooling the cylinders, pistons and piston trunk guides, in the arrangement and shaping of the passages and ports, in means for equalizing pressure in the combustion chambers; in the provision of means for supercharging with air, in certain features oi thelubricating system and in other details of construction as hereinafter described and then definitely claimed.

In the drawin s:

Fig. 1 is a vertical section of an engine constructed in accordance with my invention;

Fi 2 a similar view of part of the engine with the trunk pistons in a different position;

Fig. 3 a side elevation of the engine;

Fig. 1 a cross section on the line t l in Fig. l;

Fig. 5 a cross section on the line 55 in Fig. 1;

Fig. 6 a cross section on the line 66 in Fig. 1; i

Fig. 7 a longitudinal section of theconnecting rod, gudgeon pin and bearings;

Fig. 8 a front elevation of the trunk pistons and their connecting cross head and fluidcooling connections;

Fig. 9 a side elevation of the trunk piston and its connecting means;

Fig. 10 a view similar to Fig. 2 showing a modification of the port arrangement;

Fig. 11 a longitudinal section of a trunk piston in which the trunk is fluid cooled;

Fig. 12 a side elevation of part of the same with its fluid connections;

Fig. 13 a cross section on the line 1313 in Fig. 11; and

Fig. 14. a side elevation, partly broken away, of a. stationary piston showing the water connections therefor.

In the drawings like numerals of rerereiicc indicate corresponding parts in the different figures.

An engine in accordance with my invention is constructed, as is common, with a base 1, cylinder block 2, and .column 3 connecting the two. This column is preferably of an open type and is provided intermediate of its ends with the cross bar 4:, which is hollow for a purpose which will hereinaitterappear.

The engine block is formed with two cylinders 5', arranged side by side, so that two pistons may operate on a single connecting rot and so that scavenging may occur seriatim through the combustion chambers of both cylinders. In each cylinder is longitudinally movable a trunk piston 6, the sleeves 7 of these pistons being connected by a cross head carrying the gudgeon pin 8 oi"- the connecting rod 9, the lower end of which is journalled on a crank 10 of the crank shaft 11, which has its hearings on the base 1.

In the preferred construction the cross head is formed in two parts 12 in which the gndgeon pin 8 is secured. These parts 12 are formed with ribs 13 interlocking with the ribs 14E formed on the sleeves 7 so as to relieve the fastening bolts 15 of the driving stress. Within the sleeve of each trunk piston is located a stationary piston 16. Each stationary piston is preferably supported from the cross bar 4% of the column 3. I show each of these stationary pistons as carried by two tubes 17. provided at each end with flanges, by means of which they are secured to the stationary piston head and the cross bar. The piston heads are hollow for the circulation of a cooling fluid.

It will be noted that the cross bar 4 is divided by a partition 18 into two chambers. With one of these chambers pipes 19 communicate and with the other pipes 2O, which pipes are led up through the tubes 17, one of each pair reaching only to the lower part of the interior of the hollow head of the corresponding stationary piston and the other preferably extending to a point adjacent the top of the same. The chambers of the cross bar 4 will, of course, be connected with a suitable water cooling system.

From the construction of the cylinder and stationary and movable pistons described it follows that two pairs of combustion chambers are formed, one pair between the trunk pistons and the ends of the cylinders and the second pair between the inner sides of the heads of the trunk pistons and the stationary pistons 16. Between the outer chambers, adjacent their outer ends, is formed a passage 21. A similar passage 22 is formed between the inner ends of the inner pair of chambers at or about the level of the outer ends of the stationary pistons 16. These chambers are given an oblate spheroidal form to reduce as much as possible the area of their walls relative to the cubical contents. In the case of the passage 21 the desired shape can be more nearly approximated than in the case of the passage 22, as the parts 23 of the outer ends of the cylinders and the parts 24 of the outer ends of the pistons 6 may be shaped to con tinue approximately the curves of the inner and outer walls of the passage.

At one side of the engine is located an air manifold 25 and at the other side an exhaust manifold 26. Ports 27, 28 form a communication between the air manifold and the interior of the adjacent cylinder, and ports 29 and 30 form a communication between the exhaust manifold and the interior of the ad j acent cylinder and are adapted to be opened ahead of the air ports. Theoretically each pair of ports might be thrown into one by omitting the separating partition, but for the sake of strength they are preferably separated as shown.

The sleeve of each trunk piston is provided with. the opposite ports 31, 32, which, when the piston is at the outer end of its stroke, are in alineinent with the passage 22, the air in let port 27 and exhaust port 29. At the inner side of the sleeve of each trunk piston, adjacent the inner side of the head, is formed a port 33.

The operation of the engine as so far described is as follows: Assuming the trunk pistons to be at the outer end of their stroke, the passage 22 is in communication with both combustion chambers of the inner pair, and as one of these chambers is in communication with the air manifold and the other with the exhaust manifold, scavenging air will flow seriatim through both chambers. The course of the scavenging air when the pistons are at the inner end of their stroke will be evident on examination of Fig. 2. It will be noted that the heads of the stationary pistons adjacent the ports through which air passes over them are shaped to form deflectors 34 tending to throw the entering air towards the opposite ends of the chambers. I find, however, that better seavenging is obtained if a third passage be formed between the cylinders as shown at 35. This passage is so positioned that, according to the position of the trunk pistons, two channels are provided between the chambers of the outer pair or inner pair, as the case may be, adjacent the opposite ends thereof. Thus with either pair of chambers there is provision for some air to pass more or less directly across from the inlet manifold to the exhaust manifold, while part is required to circulate through the chambers.

If it is desired to use supercharging air the passage 35 must be increased in length, as shown in Fig. 10, so that it will form a communication between the chambers of either one pair or the other when the trunk pistons are at the inner or outer ends of their stroke and after the inlet and exhaust ports are closed. Either high or low pres sure supercharging air may be introduced for purposes known in the art.

Each of the passages 21 and 22 is provided with one or more pairs of fuel injection valves 37, the valves of each pair being arranged in opposed relationship to discharge towards one another so that trouble due to the discharging of fuel against opposed metal surfaces is overcome. So also the danger of complete failure of fuel supply to the passages is materially reduced. Suitable connections for the connection of starting valves, relief Valves and indicators will be provided in connection with the passages 21 and 22 for use as known in the art. Suitably timed mechanism, such as is known in the art, will be provided to cause the periodic injection of fuel at the proper times and for a suitable period of each stroke. 7

It is desirable that after the termination of the period of fuel injection means for equalizing the pressure between the chambers of the inner pair should be provided. For this purpose I form the ports 38 in the inner sides of the sleeves of the trunk pistons. These come into register with the passage 22 almost immediately after fuel injection has ceased and remain in register sufficiently long for equalization, if necessary, to take place.

Cooling system As the engine described is double acting and works on a two-stroke cycle, it develops a large amount of power for its size and the waste heat is therefore very considerable. A very complete cooling system is therefore required.

The method of cooling the stationary pistons has already been described when describing their construction and arrangement.

Provision must further be made for the effective cooling of the cylinders, the movable pistons, and preferably also the sleeves of these pistons and the guides which are provided for guiding the lower ends of the sleeves. The cylinders preferably have their walls made thin, as shown, and stiffened and strengthened by means of ribs 39, which also serve to increase the heat radiating surfaces of their outer walls. A water jacket is formed around the cylinder block by the sheet metal shell 40, which is secured in place in a known manner, but which is provided with circumferential corrugations 41 which permit of its expansion and contraction without straining its connections. Suitable water con nections 42 are provided, which will, of course, be connected in practice with a water circulating system. The heads of the trunk pistons 6 are hollow, as shown, and passages are formed in the sleeves 7 communicating there with. The lower ends of these passages are connected with telescopic tubes 44 connected with suitable means for circulating oil or other cooling fluid. Certain of these passages, by means of tubes 45, are extended to reach the outer parts of the hollow heads, while other passages communicate directly with the inner sides of the fluid space in the heads, thus providing for effective circulation.

In the modification shown in Figs. 11 to 13 of the drawings the passages in the sleeve of the piston are materially increased in cross sectional area so as to provide water cooling for the sleeve.

ater cooling for the sleeves of the trunk pistons is also provided, by means of the sleeve guides 46, which are arc-shaped in cross section and are supported in position against the outer sides of the sleeves, preferably by being bolted to flanges 47 on the column 3. These guides are hollow and are connected, by means of the pipes 48, to the chambers of the cross bar 4, one pipe running to the upper end of each guide and another to the lower end, whereby effective circulation is provided.

Lubrication Forced lubrication to the Various moving parts will be provided but, as the principles of forced lubrication are well known, only those features which are peculiar to the present invention will be described. Oil for the outer surfaces of the trunk pistons is supplied through the duct 49, which communicates with one of the annular ducts 50, communieating with holes formed in the walls of the cylinders. A duct 51 connects these annular ducts and a duct 52 provides an outlet. A similar system of annular ducts 53 and ducts 54, 55 and 56 provides means for lubricating the lower parts of the sleeves. The inner surfaces of the sleeves are lubricated, by means of ports 57, which at a certain point in the stroke of the pistons come into alinement with the annular ducts 53, thus allowing oil to pass through into annular ducts 58 co1nmu-. nicating with holes formed in the walls of the heads of the stationary pistons. Oil ducts 59 provide means for lubricating the sleeve guides 46. The gudgeon pin is a part which requires to be thoroughly oiled, and I therefore provide means for conveying oil directly to its bearing surfaces. Telescopic oil pipes 60 are provided connected with the ends of a passage 61 formed through the udgeon pin, and the passage 62 connects the passage 61 with the bearing surfaces of the pin. Through the connecting rod 9 is formed the passage 63 extending from hearing to bearing. Oil is thus led directly to the gudgeon pin bearing, thence passing to the lower bearing of the connecting rod.

In Fig. of the drawings I show a modification of the porting arrangement of the engine. In the arrangement shown in Figs. 1 and 2 the hot exhaust is all on one side and the cool scavenging on the other side, which in a large engine may result in stresses due to unequal. expansion of the parts. To overcome this difficulty I show in Fig. 10 a combined exhaust and inlet manifold at each side of the engine, each manifold being divided by a partition 64. The flow of scavenging air for the outer pair of chambers is from the air manifold across through the port 28, the passages 21 and 35 and through the port to the exhaust manifold 26*. The flow through the inner pair of chambers is in the reverse direction from the air manifold 25, through the inlet port 28 the ports 31, 32, the passages 22 and and through the port 29" to the exhaust manifold 26'.

It will be noted that both ends of the heads of the trunk pistons are concave and the ends of the stationary pistons are convex, thus giving the combustion chambers a form well adapted for the circulation of the scavenging air through the chambers.

It will be understood, of course, that the usual auxiliary apparatus for compressing air for starting and running, for injecting fuel,

for circulating cooling water and for circulating oil well known in the art may be employed.

While the engine is shown as adapted to operate on the Diesel plan, many of its features are adapted, with little change, for use on the semi-Diesel plan or with an explosive mixture.

What I claim as my invention is:

1. An internal combustion engine includ ing two cylinders arranged side by side; a trunk piston fitted in each cylinder; a. sta tionary piston fitted in the sleeve of each trunk piston, whereby two combustion chambers are formed, one between the trunk piston and the end of the cylinder and one between the inside of the head of the trunk piston and the stationary piston; and ports and passages in the cylinder walls and ports in the trunk pistons whereby air or gases may be caused to flow seriatiln through either pair of combustion chambers according to the position of the trunk piston, the passages between the chambers being three in number and positioned relative to the outer ends of the cylinders and the upper ends of the stationary pistons so that when scavenging is taking place two channels are provided between the chambers of one pair or the other, as the case may be, adjacent the opposite ends thereof.

2. In an internal combustion engine including two cylinders arranged side by side; a trunk piston fitted in each cylinder; a stationary piston fitted in the sleeve of each trunk piston, whereby two combustion chambers are formed, one between the trunk piston and the end of the cylinder and one between the inside of the head of the trunk pis ton and the stationary piston; a passage connecting the outer ends of the cylinders; a passage connectin the cylinders in substantial alinement with the upper ends of the stationary pistons; an inlet port in one cylinder and an exhaust port in the other cylinder in substantial alinement with the last mentioned passage adapted to be controlled by the sleeve of the trunk piston; ports in the trunks of the pistons adapted to form a communication between the interiors of said trunks and the last mentioned passage when the inlet and exhaust ports are open to said interiors; and supplementary ports in the trunks oi the pisstons for equalizing the pressure between the chambers of the inner pair through the last mentioned passage and after fuel ignition.

3. In an internal combustion engine including two cylinders arranged side by side; a trunk piston fitted in each cylinder; a stationary piston fitted in the sleeve of each trunk piston, whereby two combustion chambers are formed, one between the trunk pis ton and the end of the cylinder and one be tween the inside of the head of the trunk piston and the stationary piston; a passage connecting the outer ends of the cylinders; a

passage connecting the cylinders in substantial alinement with the upper ends of the stationary pistons; an inlet port in one cylinder and an exhaust port in the other cylinder in substantial alinement with the last mentioned passage adapted to be controlled by the sleeve of the trunk piston; ports in the trunks of the pistons adapted to form a communication between the interiors of said trunks and the last mentioned passage when the inlet and exhaust ports are open to said interiors; and means associated with each of the passages atoresaid for effecting combustion, said passages being of oblate spheroidal form.

4, In an internal combustion engine including two cylinders arranged side by side; atrunk piston fitted in each cylinder; a sta tionary piston fitted in the sleeve of each trunk piston, whereby two combustion chambers are formed, one between the trunk piston and the end of the cylinder and one between the inside of the head of the trunk piston and the stationary piston; a passage connecting the outer ends of the cylinders; apassage conecting the cylinders in substantial alinement with the upper ends of the stationary pistons; an inlet port in one cylinder and an exhaust port in the other cylinder in substantial alinement with the last mentioned passage adapted to be controlled by the sleeves of the trunk piston; ports in the trunks of the pistons adapted to form a communication between the interiors of said trunks and the last mentioned passage when the inlet and exhaust ports are open to said interiors; and means associated with each of the passages aforesaid for effecting combustion, said passages being of oblate spheroidal form, the outer ends of the cylinders and the adjacent edges of the ends of the pistons also being shaped to continue approximately the curves of the inner and outer walls of the passage first mentioned.

5. In an internal combustion engine including two cylinders arranged side by side; a trunk piston fitted in each cylinder; a sta tionary piston fitted in the sleeve of each trunk piston, whereby two combustion chambers are formed, one between the trunk piston and the end of the cylinder and one between the inside ot' the head of the trunk piston and the stationary piston; a passage connecting the outer ends 01" the cylinders, said passage being of oblate spheroidal form and the outer ends of the cylinders and the adjacent edges of the pistons also being shaped to continue approximately the curves of the inner and outer walls of the passage; a passage connecting the cylinders in substantial alinement with the upper ends of the stationary pistons; an inlet port in one cylinder and an exhaust port in the other cylinder in substantial alinement with the last mentioned passage adapted to be controlled by the sleeves of the trunk piston; ports in the trunks of the pistons adapted to form a communication between the interiors of said trunks and the last mentioned passage when the inlet and exhaust ports are open to said interiors; and means associated with each of the passages aforesaid for causing combusion.

6. An internal combustion engine includ- 'ig two cylinders arranged side by side; a trunk piston fitted in each cylinder; a stationary piston fitted in the sleeve of each trunk piston, whereby two combustion chambers are formed, one between the trunk piston and the end of the cylinder and one between the inside of the head of the trunk piston and the stationary piston; and ports and passages in the cylinder walls and ports in the trunk pistons whereby scavenging air may be caused to flow seriatim through either pair of combustion chambers according to the position of the trunk pistons, the passages in the cylinder walls connecting the combustion chambers each being provided with opposed fuel injection jets.

7. An internal combustion. engine as set forth in claim 2 in which the intermediate passage is provided with means for the introduction of supercharging air.

8. An internal combustion engine including two cylinders arranged side by side; a trunk piston fitted in each cylinder; a stationary piston fitted in the sleeve of each trunk piston, whereby two combustion chambers are formed, one between the trunk piston and the end of the cylinder and one between the inside of the head of the trunk piston and the stationary piston; ports and passages in the cylinder walls and ports in the trunk pistons whereby scavenging air may be caused to flow seriatim through either pair of combustion chambers according to the position of the trunk pistons; and in which a double cross head is provided, the parts carrying a gudgeon pin and being secured to opposite sides of the lower ends of the sleeves of the trunk pistons.

9. An internal combustion engine including two cylinders arranged side by side; a trunk piston fitted in each cylinder; a stationary piston fitted in the sleeve of each trunk piston, whereby two combustion chambars are formed, one between the trunk piston and the end of the cylinder and one between the inside of the head of the trunk piston and the stationary piston; ports and passages in the cylinder walls and ports in the trunk pistons whereby scavenging air may be caused to flow seriatim through either pair of combustion chambers according to the position of the trunk pistons; and in which a double cross head is provided, the parts carrying a gudgeon pin and being secured to opposite sides of the lower ends of the sleeves of the trunk pistons, the cross head parts and the sleeves being formed with inter-engaging ribs to relieve the fastenings of strain.

10. An internal combustion engine including a pair of cylinders; a base; a column connecting the cylinder and base and formed with a hollow cross bar intermediate of its ends divided into two chambers for cooling fluid and formed with a central gap; trunk pistons fitted in the cylinders; stationary pistons fitted in the trunk pistons, supported on the hollow cross bar and formed with hollow heads; pipes extending from the chambers of the cross bar to the interior of the heads of the stationary piston for the circulation of fluid; a cross head connecting the trunk pistons; a connecting rod pivotally connected with the cross head and extending down through the gap in the hollow cross bar; and a crank shaft journalled in the base and with which the connecting rod is connected.

11. An internal combustion engine constructs d as set forth in claim 10 provided with liquid-jacketed guides for the inner ends of the sleeves of the trunk pistons carried by the column and circulating pipes connected with the chambers of the cross bar of the column.

Signed at Toronto, Ontario, this 5th day of October, 1927.

ADAM CRAIGON. 

